An extensive system of storms that flattened homes, flooded neighborhoods and triggered tornadoes split, reignited and threatened yet more damage Monday.

The severe weather battered a vast area from New Hampshire to North Carolina and from Michigan to northern Louisiana on Sunday. Six tornadoes reportedly touched down, more than 200,000 customers were left without power and thousands of flights were canceled or delayed.

Early Monday, the Northeast began seeing the first evidence of another tumultuous day, with New York City bearing the early brunt. Heavy rain and localized flooding were reported, while Long Island was experiencing thunderstorms, Weather Channel lead meteorologist Kevin Roth said.

After a short break in late morning, the system was expected to spread to New England and West Virginia on Monday afternoon.

While Sunday's storm covered one large area, Monday's bout of extreme weather was forecast to impact on two sections of the country. After its northern section batters the Northeast, the South was set to be slammed in the afternoon. Roth said strong straight-line winds were predicted to do damage from North Carolina across the Gulf Coast to New Orleans.

Tennessee was particularly hard hit by Sunday's storms. Four tornadoes were reported to the National Weather Service across the state — one of these could have been responsible for flattening 10 homes just north of Knoxville. Another tornado was confirmed in Wolcott, Connecticut, at 12:50 p.m., and another was reported but unconfirmed in Ritchie, West Virginia, just after 8 p.m.

By 11 a.m. ET on Monday, 196 flights were canceled and 1,300 more delayed across the U.S. and Canada, according to FlightStats.com. The worst affected airports were Philadelphia International and Detroit Metropolitan, both of which were in the path of the bad weather. On Sunday, there were more than 500 cancellations and nearly 7,000 delays nationwide.